Research On Preparation Of Solid Self-lubricating Antifriction Coating Of Steel Substrate Surface And Its Tribological Behaviors

In this paper,steel 45 is used as the substrate,and phosphating treatment is carried out on its surface,after which the solid self-lubricating antifriction coating is prepared on the surface,and its preparation process and friction and wear behaviors of antifriction coating are studied.The main research work is as follows:Firstly,the preparation technology of adhesive by using epoxy resin E51,low molecular polyamide 650 and DDM/m-PDA mixed curing agent is studied,and the tensile,shear and heat resistance properties of the adhesive are discussed.The research shows that: the tensile and shear strength of the adhesive increases as the amount of low molecular polyamide 650 increases,of which the tensile and shear strength of the adhesive surface can reach 16.8 MPa after being subject to grinding + corrosion + coupling agent treatment for the adhesive whose ratio of epoxy resin E51 and low molecular polyamide 650 is 5:4.Also,the adhesive has good heat resistance,and its tensile and shear strength can reach 11.3 MPa when the ratio of epoxy resin E51,low molecular polyamide 650 and DDM/m-PDA mixed curing agent is 5:1:0.75.Secondly,the preparation technology of adhesive-type solid self-lubricating composite by using adhesive,nano-graphite,nano-molybdenum disulfide and carbon fiber powder as well as its friction and wear behaviors are studied.The research shows that: nano-graphite can reduce the friction coefficient of the composite.The friction coefficient is 0.215 and the wear rate is 6.21 when 24wt% nano-graphite is added.In addition,nano-molybdenum disulfide will be subject to oxidation and turn into in the process of friction,which has no antifriction effect,but can improve the abrasive resistance of the composite;nano-graphite and nano-molybdenum disulfide have synergistic effect on reducing friction coefficient and improving wear resistance.The friction coefficient is 0.22 and the wear rate is 4.61 when the total amount of nano-graphite and nano-molybdenum disulfide(3:2)is 24wt%.The addition of carbon fiber powder is conducive to the formation of transfer film,which can reduce the friction coefficient and wear rate;the composite has good antifriction and wear resistance property,and its friction coefficient is 0.137 and wear rate is 2.35 when 24wt% nano-graphite and molybdenum disulfide(3:2)is added,while 8wt% carbon fiber powder is added.Thirdly,the preparation technology of adhesive-type solid self-lubricating composite coating material on the phosphating film which is prepared on substrate steel 45 and its friction and wear behaviors are studied.The research shows that: the phosphating film contains a large number of fine short rod-shaped crystal with large gap and distributed uniformly,which can increase the adhesive area with the solid self-lubricating composite coating material,thereby enhancing the adhesive strength.When the thickness of solid self-lubricating composite coating is 0.1mm,the coating failure time is 350 min and 180 min respectively through comparing the friction and wear for the specimen with phosphating film after being treated by coupling agent with that of the specimen without phosphating film.